Dithio-and thiono-carbamate mineral value collectors

ABSTRACT

A NEW COMPOSITION OF MATTER AND AN IMPROVEMENT IN THE CONCENTRATION OF ORES BY FLOTATION WHICH COMPRISES SUBJECTING A SULFIDE ORE IN THE FORM OF A PULP TP A FLOTATION PROCESS IN THE PRESENCE OF AN EFFECTIVE QUANTITY OF A FLOTATION COLLECTOR COMPRISING A NEW COMPOSITION OF MATTER CORRESPONDING TO THE FORMULA   A-R1-NH-C(=S)-Y-R2   WHEREIN A IS A RADICAL CORRESPONDING TO THE FORMULA   R-X-C(-X&#39;&#39;-R&#39;&#39;)(-R3)- OR (-X&#39;&#39;-CH(-Z&#39;&#39;)-CH(-Z)-X-)&gt;C(-R3)-   X AND Y CONSIST OF -S- OR -O-; R, R&#39;&#39;, Z, Z&#39;&#39; AND R2 ARE HYDROCARBYL GROUPS, R1 IS AN ALKYLENE GROUP AND R3 IS H OR LOWER ALKYL GROUP. CERTAIN OF THE INDICATED COMPOUNDS PROVIDE FOR ENHANCED SELECTIVITY AND/OR RECOVERY OF SULFIDE MINERALS OF CU, ZN, MO, CO, NI AND PB OVER IRON SULFIDE.

United States Patent s 787 471 nrrrno- AND THION'O-CARBAMATE MINERAL VALUE COLLECTORS Guy H. Harris, Concord, Calif., and Terry D. Filer, Idaho Falls, Idaho, assignors to The Dow Chemical Company,

Midland, Mich.

No Drawing. Original application Feb. 13, 1969, Ser. No. 799,071, now Patent No. 3,590,997. Divided and 11115 application Mar. 4, 1971, Ser. No. 121,212

Int. Cl. C07c 155/08 US. Cl. 260-455 A 8 Claims ABSTRACT OF THE DISCLOSURE wherein A is a radical corresponding to the formula X and Y consist of S-- or O--; R, R, Z, Z' and R are hydrocarbyl groups, R is an alkylene group and R is H or a lower alkyl group. Certain of the indicated compounds provide for enhanced selectivity and/or recovery of sulfide minerals of Cu, Zn, Mo, Co, Ni and Pb over iron sulfide.

This application is a division of Ser. No. 799,071, filed Feb. 13, 1969, now US. Pat. 3,590,997.

BACKGROUND Flotation is a process of treating a mixture of finely divided mineral solids, e.g. a pulverulent ore, suspended in a liquid whereby a portion of such solids are separated from other finely divided mineral solids e.g. clays and the like materials present in the ore, by introducing a gas into the liquid (or providing a gas in situ) to produce a frothy mass containing certain of the solids on the top of the liquid, and leaving suspended (unfrothed) other solid components of the ore. Flotation is based on the principle that introducing a gas into a liquid containing solid particles of different materials suspended therein causes adherence of some gas to certain suspended solids and not to others and makes the particles having the gas thus adhered thereto lighter than the liquid. Accordingly, they rise to the top of the liquid to form a froth.

Various flotation agents have been admixed with the suspension to improve the frothing process. Such added agents are classed according to the function to be performed: Collectors, e.g. high carbon chain compounds such as collectors for sulfide minerals including Xanthates, thionocarbamate, and the like; frothers which impart the property of forming a stable froth, e.g. natural oils such as pine oil and eucalyptus oil; modifiers such 3,787,471 Patented Jan. 22, 1974 as activators to induce flotation in the presence of a collector, e.g. copper sulfate; depressants, e.g. sodium cyanide, which tend to prevent a collector from functioning as such on a certain mineral which it is desired to retain in the liquid, and thereby discourage a substance from being carried up and forming a part of the froth; pH regulators to produce optimum metallurgical results, e.g. lime, soda ash, and the like.

It is of importance to bear in mind that additaments of the above type are selected for use according to the nature of the ore, the mineral sought to be recovered, and the other additaments which are to be used in combination therewith. l I

An understanding of the phenomena which makes flotation a particularly valuable industrial operation is not essential to the practice of the present invention. They appear, however, to be largely associated with selective, afiinity of the surface of particulatedsolids, suspended in a liquid containing entrapped gas, forthe liquid on one hand and the gas on the other. f I

The flotation principle is applied in a number 'of mineral separation processes among which is the selective separation of such minerals as sulfide copper minerals, sulfide zinc minerals, sulfide molybdenum minerals and ICC others from sulfide iron minerals. The present invention DESCRIPTION OF THE INVENTION The novel compounds of the present invention correspond to the general formula (a) R, is an alkylene group containing up to about 10 carbon atoms, preferably up to about 5 carbon atoms;

(b) R; is a hydrocarbyl group, other than an aryl group wherein an atom in the ring structure is bonded directly to Y;

(c) Y is S- or O; and (d) A is a radical corresponding to the formula wherein v (i) R is H or a lower alkyl group containing up to about 7 carbon atoms and preferably up to about 3 carbon atoms; and,

(ii) when R, is an alkyl group, X and X are both (iii) when X and X are both O- and R is a lower alkyl group, R and R are independently an alkyl, alkenyl, cycloalkyl or cycloalkenyl group containing up to about 7 carbon atoms and preferaby up to 3 carbon atoms;

(iv) when X and X are both -S-- and R is a lower alkyl group, R and R are the same alkyl, alkenyl, cycloalkyl or cycloalkenyl group containing up to about 7 carbon atoms and preferably up to about 3 carbon atoms; l A

- (v) when R is H, X and X are independently S- or O- and R and R are independently an alkyl, alkenyl, cycloalkyl or cycloalkenyl group containing up to about 7 carbon atoms and preferably up to 3 carbon atoms; 7

or (2) A is a radical corresponding to the formula wherein X and X are independently -O- or -S; Z and Z are independently H, or an alkyl group containing up to about 5 carbon atoms and preferably up to about 3 carbon atoms, and R is H or an alkyl group containing up to 7 carbon atoms, preferably up to 3 carbon atoms.

Preferably R is a member selected from the group consisting of an alkyl or alkenyl group containing up to l8 carbon atoms, preferably up to about 10 carbons; a cycloalkyl, or cycloalkenyl group containing up to about 8 carbon atoms, or an aralkenyl or aralkyl group wherein the alkyl or alkenyl portion contains up to about 5 carbon atoms and is bonded to Y.

The novel compounds can be prepared, for example, by reacting an aminoacetal, aminoketal, aminothioacetal or aminothioketal compound corresponding to the forwherein R, R, X, X, Z, Z", R and R are the same as defined hereinbefore, with a Xanthate ester corresponding to the formula wherein R is the same as defined hereinbefore and R is usually a lower alkyl group such as methyl or ethyl. A mercaptan R SH is evolved during the reaction.

The compounds as defined herein are particularly suitable for use in standard flotation processes as flotation collectors to concentrate copper sulfide and other like minerals from sulfide ores. In such processes a pulp is first prepared by wet grinding the ore to a suitable size with or without a pH modifier. A suitable frothing agent is then added, e.g., pine oil, cresylic acid, polyalkoxyparafiin and the like. An effective quantity of a compound as defined herein is then added, preferably ranging from about 0.01 lb. to about 0.25 lb. per ton of pulp and the pulp is then agitated and aerated. The copper minerals and other like sulfide minerals collect as a froth which is readily overfiowed or skimmed oil from the residual gangue and non-desired materials and the metal values therein recovered.

The following examples will facilitate a more complete understanding of the present invention but they arenot meant to limit the scope of the invention to the specific embodiments incorporated therein.

4 EXAMPLE 1 One species of a compound within the scope of the present invention and corresponding to the formula 1 ll (CzHaOhCH-OHzN-C-O-CH CHzCHKJHs):

was prepared in the following manner.

To 192 grams of EXAMPLE 2 Another compound within the scope of the present invention corresponding to the formula (CzH5O)zCHCH2D{IC-OCH(CH3)2,

was prepared in the following manner:

In a manner similar to that described in Example 1, 13.2 grams of distilled was reacted with 11.7 grams of H NCH CH(OC H A percent yield of product was obtained. The structure of the compound set forth above was confirmed for the product by infrared and NMR analysis. Partial calculated analysis for the compound is C, 52.98%; H, 9.00%; and N, 5.95%. Actual partial analysis of the product obtained was C, 50.6%; H, 8.5%; and N, 6.3%.

EXAMPLE 3 Another compound within the scope of the present invention, corresponding to the formula was prepared in the following manner. To 13.8 grams of dimethyl trithiocarbonate was added 16.1 grams of the diethyl acetal of 4-aminobutanal. The temperature of the reaction mixture rose to about 50 C. with the evolution of CH SH. The reaction was completed by heating the mixture at a temperature of from about 55 to 60 C. under areduced pressure of about 30 mm. until CH SH was no longer evolved. The product was an oil, obtained in about 92% yield. The above assigned structure for the compound was confirmed by infrared and NMR analysis.

Other species of compounds within the scope of the present invention were prepared in a manner similar to that defined in the previous examples. The compounds corresponded to the following formula:

ll (CHsCH2O)zCH(OH2) NECO CHzCHa Calculated partial analysis is C, 52.98%; H, 9.30%'

V EXAMPLE 4 Various novel compounds Within the scope of the present invention were employed in a flotation separation of copper sulfide from an ore obtained from the southwestern United States. A standard flotation collector compound corresponding to the formula CHaGH21 I-i JCH(CH was employed as a control.

An ore sample was ground for minutes at a pulp density of 59% solids together with 0.6 lb./ton of lime. The pulp was then diluted and conditioned for 2 minutes with the indicated amount of a collector compound, listed in Table I, and 0.088 lb./ton of frother. The pH of the pulp was 9.4. Flotation was then carried out for 8 minutes. The concentrate and tailings obtained were dried 6 This compound can then be contacted 'with thionyl chloride and a base to provide a compound corresponding to the formula 3 v .0 I E g 0 condensed in the presence of SnCl with an alkylene oxide,

0 and assayed. The results obtained, the collector com- Z -C-CZ pounds and amount employed are set forth in the following Table I. v H H TABLE I Lbs/ton Percent Cu Run No. Collector compound added recovered Control--- Control 0.016 81.1 Do do 0.032 82.1 Do on 0.160 82.8 Do fin 0. 240 83.5

oln onortommrouooornomom 0 2... ointonomcnomm oomen, 0.010 83.2

3 Same as above--- O. 032 80. 4 4 fin 0.160 81.4

(GzH5O)rCHCHaNHCOCH(CH 6 Same as above-.:....:;:;:-..;-;-:.--;.;..;;.:;;: 0. 240 83. 2

( i )2CH(CHa)aNHC S CH;

8 Same as above---- 0.032 82. 5 9 do 0. 160 82. 6

N-Rg-COOH in an anhydrous solvent to give a compound corresponding to the formula tan 7 wherein R is H. Treatment with hydrazine gives the cyclic aminoacetal corresponding to the formula H (HE-z HgN-lh-C I I R: H wherein Z, Z' and R are the same as defined hereinbefore and R is H.

Cyclic aminoketals i.e. compounds corresponding to the general formula wherein Z, Z, and R are the same as defined hereinbefore and R is a lower alkyl group, can be prepared in the following manner. A chloro or bromo ketone is reacted with a phthalimide salt. The product is condensed in the presence of SnCL; with an alkylene oxide in an anhydrous solvent, and the resulting product treated with hydrazine to produce the cyclic aminoketal. The sequence of the reaction steps can be summarized as follows Other cyclic species can be prepared by the condensation of cyano or nitro substituted ketones or aldehydes with epoxides, followed by the reduction of the cyano or nitro group to the NH group.

Non-cyclic aminoacetals can be made by known methods for converting carbonyl compounds to the corresponding acetal or ketal, employing carbonyl compounds substituted with cyano or nitro groups and then efiecting reduction of the groups to the NH; group, and also by employing certain aminocarbonyl compounds directly. Also, aminoacetal and aminoketal compounds, both cyclic and non-cyclic, can be made by amination of halo acetals etc., the latter compounds being prepared by halogenation of carbonyl compounds prior to their conversion to the acetals or ketals by known methods. Wagner and Zook, Synthetic Organic Chemistry, pp. 261-275, 1953, can be referred to for detailed description of various procedures for preparing various acetals and ketal starting materials employed in the present invention.

The xanthate starting materials can be prepared for example, by reacting an alkali metal alkoxide 1 with CS To prepare the alkoxide of a. tertiary alcohol a separate preliminary reaction with potassium metal is employed.

8 and then with methyl chloride. The reaction is represented by wherein R is the same as defined hereinbefore and K represents an alkali metal. Suitable alcohols include cyclohexanol, cyclohexenol, allyl alcohol, cinnamyl alcohol, crotyl alcohol, 2,3,5-trimethy1-3-hexanol; 2,3,4-trimethyl- 2-hexanol and other like alcohols.

Both cyclic and non-cyclic aminothioacetals and aminothioketals can be prepared in a manner similar to those previously described for the preparation of the cyclic and non-cyclic aminoacetal and aminoketal compounds. A process for preparing dithiolane acids and esters is taught in US. Pat. No. 2,839,445. The so prepared compounds can be converted by methods known in the art to the corresponding nitriles or amides and the latter reduced to the amine intermediates which can then be reacted with suitable xanthate compounds to provide compounds with in the scope of the present invention. One specific compound within the scope of the present invention is prepared in the following manner: To 13.6 grams of methyl ethyl xanthate is added 12.9 grams of 3,3-bis(ethylthio)- propyl amine. After the spontaneous evolution of methyl mercaptan ceases the reaction mixture is heated at 60 C. under reduced pressure to complete the removal of the mercaptan. The product, an oil, corresponding to the formula CzHrS H is produced in substantially quantitative amounts.

Other aminoacetals which can be employed to prepared compounds within the scope of the present invention wherein A-- corresponds to the radical are prepared in the following manner. An aldehyde com.- pound corresponding to the formula This compound is reacted with R'SNa to form the compound S-R1 i and this compound treated with hydrazine to give the aminoacetal starting material.

Other novel compounds which can be prepared by a method as defined hereinbefore and which are useful as flotation collectors in the concentration of sulfide compound containing ores include for example:

Various modifications may be made in the present invention without departing from the spirit or scope thereof for it is understood that we are limited only as defined in the appended claims.

10 What is claimed is: 1. A composition of matter corresponding to the formula 3. The composition of matter as defined in claim 1 corresponding to the formula 4. The composition of matter as defined in claim 1 corresponding to the formula 5. The composition of matter as defined in claim 1 corresponding to the formula 6. The composition of matter as defined in claim 1 corresponding to the formula 7. The composition of matter as defined in claim 1 corresponding to the formula S (CHaOhOHCHzNHHl-O 0 H 8. The composition of matter as defined in claim 1 corresponding to the formula S (CHaOhCHCH NH -O CHzCHa References Cited UNITED STATES PATENTS 3,464,551 9/ 1969' Falvey 209-166 3,057,710 10/1962 Harman et a1 260-455 A 3,425,550 2/1969 Baarson et al 209-166 3,297,680 1/1967 Hamm et a1 260-455 A 3,277,142 10/1966 Zerbe et a1. 71-101 FOREIGN PATENTS 1,031,738 6/1966 Great Britain 260-455 A OTHER REFERENCES Brown: Penilloaldehydes and Pevaldic Acids, Etc., (1949), CA, 44, pp. 146-53 (1950).

Muehlbauer: Improved Syn. of N-Subs. Thiocarbamic Acid, Etc., (1964), CA, 60, p. 10559 (1964).

GLENNON H. HOLLRAH, Primary Examiner US. Cl. X.R. 260-347.2

22 3? UNITED STATES PATENT OFFICE v CERTIFICATE OF CORRECTION Patent No. 3,7 T, 7 Dated January 22, 197

Inventor(s) Guy H. Harris and Terry D. Filer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Column 3, formula line 10 should be as follows Column h line 71 should readf Column 5, Table I, Item 1 should read:

Column 6, line o, formula should read:

Patent No. 3,787, rr1 Dated: January 22, 197k Inventors: Guy H. Harris and Terry D. Filer Certificate of Correction (continued) Column 7, lines 5 and 16, formulas should read:

Column 7, line &0, fomula. should read:

' Signed and sealed this 22nd day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR;

0. MARSHALL DANN- Attesting Officer Commissioner of Patents 

